The proposed Mentored Clinical Scientist Development Award would enable me to obtain the basic science training necessary to pursue my research interests in the biological basis of social communication in children with mental illness. The proposed study would compare quantifiable social communication behaviors in children with autism, children with developmental language disorder and normal children. Autism is a biologically based developmental disorder defined in part by deviance in social communication. Children with developmental language disorders also exhibit social communications and behavioral abnormalities, which seem to be relative to the degree of receptive language impairment. Despite research indicating that neuroanatomical abnormalities are involved in the etiology of both autism and developmental language disorders, the mechanisms underlying these impairments remain unknown. The high prevalence rate of communication disorders in children, and poor long term outcome of these children, underscores the need for improved understanding of the etiology of these abnormalities. The proposed study would use Magnetic Resonance Imaging (MRI) and Magnetic Resonance Spectroscopy (MRS) to investigate structural anatomy and biochemistry of the brain in these three groups of children. These structural anatomical and biochemical measures would then be examined in relation to quantifiable aspects of social communication using measures of formal thought disorder and discourse. The proposed study could contribute to our knowledge of the neuroanatomical and neurochemical abnormalities associated with the social communication deficits seen in autistic and developmental language disorders in children. This award would allow me to obtain the training necessary to pursue these research goals. The proposed training will consist of an intense basic science learning experience incorporating supervised laboratory work and didactic instruction in neuroimaging, neurodevelopment, psycholinguistics, and statistical analyses. Training in these areas will enable me to independently develop other research projects on neurodevelopment and social communication in children.